Slominski etal
suspended seat spring



Nov. 15, 1966 w.v. SLOMINSKI ETAL 3,

SUSPENDED SEAT SPRING Filed May 7, 1965 2 Sheets-Sheet 1 INVENTORS WALTER v. SLOMINSKI T16 32 GEORGE F. JANKO 1966 w. v. SLOMINSKI ETAL 3,235,597

SUSPENDED SEAT SPRING 2 Sheets-Sheet 2 Filed May 7, 1965 FIG. 2

FIG. 4

INVENTORS WALTER v. SLOMINSKI GEORGE F. .JANKO ATTORNEYS United States Patent 3,285,597 SUSPENDED SEAT SPRING Walter V. Slominski and George F. Janko, both of Lexington, Ky., assignors to Hoover Ball and Bearing Company, Saline, Mich., a corporation of Michigan Filed May 7, 1965, Ser. No. 454,101 14 Claims. (Cl. 267102) This invention relates generally to spring assemblies for seating structures and more particularly to an improved seat spring and means for assembling the spring with a Supporting frame so as to obtain an improved seating structure.v I

The spring of this invention is particularly adapted for use in upholstered furniture. In this type of seating, the back springs are conventionally mounted on an upper back rail and a lower back rail, and the seat springs are mounted on a front bottom rail and a rear bottom rail which is usually disposed below and rearwardly of the lower back rail. The lower ends of the back springs and the rear ends of the seatsprings are thus mounted on different frame rails. This arrangement is uneconomical 'in many instances and is subject to various objections from the standpoint of occupant comfort.

'It is an object of this invention, therefore, to provide an improved seat spring which is mounted at its rear end on the same frame rail on which the lower ends of the back springs are mounted, is provided adjacent its rear end with a portion which is suspended from the frame rail and which unwinds when the spring is loaded to impart a feeling of greater depth and bounce to the seat occupant, and is constructed to reduce the objectionable hammocking effect and eliminate the objectionable oil canning effect heretofore encountered in many commercial seat springs.

A further object of this invention is toprovide a seating structure spring assembly which is economical because less spring Wire, fewer spring retainers, and less seat deck material are required, than is the case in many presently manufactured seating structures, and because the requirement for spring pretensioning involved in many commercial seating structures is. eliminated, thereby enabling easier mounting of the springs on the seat frame.

, A further object of this invention is to provide a spring assembly for seat structures which provides increased occupant comfort because the discomfort caused by downward movement of the, rear ends of the seat springs relative to the lower ends of the back springs is reduced. This occupant discomfort is commonly referred to as roll up because the back spring profile to the rear of the deepest point of seat spring deflection causes a rearward pulling or gathering action on the occupants clothing resulting in increased pressure and discomfort.

A further object of this, invention is to provide a seat spring which enables spring and furniture manufacturers to achieve a higher degree of spring standardization that has heretofore been possible and enables greater flexibility in furniture design to achieve a desired outward appearance.

Further objects, features and advantages of this invention will become apparent from a consideration of the following description, the appended claims, and the accompanying drawing in which:

FIGURE 1 is a side elevational view illustrating a seating structure main frame with the seat spring of this invention and the back springs mounted thereon according to this invention, and showing the seating structure outline in broken lines;

FIGURE 2 is an enlarged detail view of a portion of the spring structure shown in FIG. 1, illustrating the structure in a deflected position in solid lines and-in an undeflected position in broken lines;

FIGURE 3 is a fragmentary top view of a portion of the structure illustrated in FIG. 2;

FIGURE 4 is a fragmentary side elevational view of a modified form of the spring mounting means of this invention, illustrated similarly to FIG. 2;

FIGURES 5 and 6 are side elevational views illustrating alternate methods for mounting the springs of this invention, illustrated similarly to FIGS. 2 and 4; and

FIGURE 7 is a fragmentary top view of a plurality of the seat springs in the assembly shown in FIG. 1.

With reference to the drawing, the improved seat spring of this invention, indicated generally at 10, is illustrated in FIG. 1 mounted on the frame 12 for a seating structure 14 such as a chair or couch. The frame 12 includes an upper back rail 16, a lower back rail 18, a rear bottom rail 20, and a front bottom rail 22. A plurality of back springs 24, only one of which is shown, are mounted on the upper and lower back rails 16 and 18. The back springs 24 are illustrated as being of the type shown in copending application Serial No. 435,000, filed'Fe'bruary 24, 1965, and assigned to the assignee of this invention, butit is to be understood that other types of back springs 24 are also usable according to the principles of this invention. A plurality of seat springs 10, only one of which is shown in FIG. 1, are mounted side by side (FIG. 7) so that they extend between the lower front rail 22 and the lower back rail 18.

Each seat spring 10 has :a front end portion 26 mounted on a retainer 28 secured to the front rail 22, a main load supporting portion 30 and a rear end portion 32 which terminates in a pair of torsion bars 34 and 36. As will be explained in detail hereinafter, the torsion bars 34 and 36 are secured to the lower back rail 18 so that the seat spring rear end portion 32 is suspended from the back rail 18. The front end portion 26 and the bracket 28 are illustrated as being of the type disclosed in copending application, Serial No. 312,459, filed September 30, 1963, and assigned to the assignee of this invention, but it is to be understood that the configuration of the spring front end portion 26 and its manner of attachment to the front rail 22 may be of other types.

The seat spring 10 and the back spring 24 are formed of what is hereinafter referred to as zigzag wire which is a term generic to both sinuous wire and formed wire, both of which terms have a well known meaning in the art. Zigzag wire includes a plurality of longitudinally spaced transversely extending torsion bars 33 (FIG. 7) and a plurality of spacer bars 35 which extend beween adjacent torsion bars. The main load supporting portion 30 of the seat spring 10 includes a plurality of torsion bars 33 and spacer bars 35 and is generally horizontal in its undeflected position illustrated in FIG. 1. Sharp bends or turns in a spring formed of zigzag wire are effected by twisting a torsion bar at each point where .a sharp turn is desired. For example, the torsion bar 40 at the rear end of the load supporting portion 30 and at the front end of the rear end portion 32 (FIG. 2) is twisted to provide for an angular relationship of the spacer bars 42 and 44 on opposite sides thereof. The

torsion bar indicated at 48 is also twisted to provide for an angular relation of the spacer bars 44 and 46 at opposite ends thereof and to form a section 50 of the spring rear end portion 32 which extends substantially horizontally at a position below the lower back rail 18. Similarly, the torsion bars indicated at 52 and 54 are twisted to provide the spring rear end portion 32 with a generally V-shape section 56 disposed rearwardly of the rail 18. The torsion bar 54 and the next to the endmost torsion bar 36 are twisted to provide them with a spring windup such that the torsion bar 36 has a tendency to move upwardly as shown in FIG. 2. and the torsion bar 34 has a tendency to move downwardly.

This arrangement facilitates mounting of the spring rear end portion 32 on the rail 18 by means of a retainer indicated generally at 58.

The retainer 58 has a body portion 60 which is positioned against the top side 62 of the rail 18 and a pair of inverted U-shape or hook shape end portions 64 and 66. The body portion 60' also has holes through which a staple '68 is extended to attach the body portion 60 to the top side 62 of the rail 18. As shown in FIGS. 2 and'3, the body portion 60 is formed with a center ridge 70, which prior to assembly of the retainer with rail 18 extends upwardly so that body portion 60 is slightly bowed in an upward direction as shown in broken lines in FIG. 2. As a result, when the staple 68 is applied with a compressed air impact tool or the like it is substantially flattened against the top side 62 of the rail 18. The retainer 58 is thus provided with the ridge 70 to prevent upward bending of the retainer 58 by the forces applied to the hook shape end portions 64 and 66 during use.

As shown in FIG. 2, the hook shape end portion 64 of the retainer 68 terminates in a spaced relation with the frame rail top side 62 to enable movement of a spring torsion bar between the frame rail top side 62 and the retainer hook shape portion 64. The hook shape end portion 66 is located rearwardly of the frame rail 18 to facilitate assembly of a torsion bar therewith also.

In the assembly of a seat spring with the frame rails 22 and 18, the spring front end portion 26 is mounted on the rail 22 by means of the retainer 28 as described in application Serial No. 312,459 referred to above. A retainer 58 is mounted on the back rail 18 at a position in line with retainer 28, and the rear end portion 32 of the spring is mounted on the retainer 58 by positioning the next to the endmost torsion bar 36 in the hook shape portion 66 and positioning the endmost torsion bar 34 against the top side of the retainer body portion 60 adjacent the hook shape portion 64. As previously explained, the torsion bars 36 and 54 are provided with a spring windup urging the torsion bar 36 upwardly as viewed in FIG. 2 and the torsion bar 34 downwardly as viewed in FIG. 2 to maintain the torsion bars in firm engagement with the retainer 58.

A back spring 24 is mounted on top rail 16 in line with the seat spring 10 and provided with a lower end portion 80 shaped so that it extends substantially horizontally adjacent the top side 62 of the frame rail 18. The 'back spring portion '80 is then assembled with the retainer 58 by positioning the end torsion bar 82 against the top side of the retainer body portion 60 adjacent the hook portion 66. The next to the endmost torsion bar 84 is then positioned in the hook shape portion 64 of the retainer 58. The torsion bars in the spring portion 80 are twisted so that :a spring windup is obtained which urges the torsion bar 82 downwardly against the top side of the retainer 58 and urges the torsion bar 84 upwardly into firm engagement with the hook shape portion 64.

It can thus be seen that in a seating structure formed according to this invention, the seat springs 10 and the back springs 24 are both mounted on the lower back rail 18, and a common retainer 58 can be utilized for each pair of seat and back springs 10 and 24, which are preferably arranged in pairs on the frame 12 to reduce the number of retainers 58. As shown in FIG. 1, this eliminates the necessity for extending the seat springs 10 all the way back to the rear bottom rail 20, thus reducing the amount of wire that is required and reducing the amount of seat deok cover material which is conventionally placed over the spring deck formed by a plurailty of spring load supporting portions 30 (FIG. 7).

In use, the seat springs 10 are tied together at the rear end of the load supporting portions 30 by means of a tie member 86 (FIGS. 1 and 7), formed of paper cord or the like, which is secured by spring clips 88 to the torsion 'bars 40. As a result, the load supporting portions 30' for the springs 10 act together. As shown in FIG. 1, the

torsion bars 40 are disposed forwardly of and in closely spaced relation with the lower frame rail 18. From the torsion bar 40, the spring rear end portion 32 extends downwardly and rearwardly to the torsion bar 48, thence rearwardly in a generally horizontal direction below the rail 18 to the torsion bar 52, thence rearwardly and upwardly to the torsion bar 54 and then upwardly and forwardly to the torsion bar 36 where the spring 10 is attached to the rail 18 by means of the retainer 58. As a result, when a downwardly directed seating load is applied to the load supporting portion 30, the spring rear end portion 32 is moved downwardly and rearwardly, as shown in FIG. 2, tending to unwind the twisted to-rsion bars in the portion 32. In other words, the load tends to twist the torsion bars in directions opposite to the direction in which they were originally twisted to shape the spring end portion 32. This unwinding of the spring rear end portion 32 imparts to the seat occupant a feeling of depth and bounce which is desirable ,in seating structures. The normal seating loaad tends to move the torsion bar 36 upwardly and tends to pivot the torsion bar 34 in a downward direction. During shock loading of the portions 30 this tendency is reversed.

Because the spring rear end portion 32 deflects in a reanward direction 'under load, the magnitude of the downward movement of the rear end of the load supporting portion 30 relative to the lower ends of the back springs 24 is reduced to a practical minimum consistent with seat comfort, thus measurably reducing roll up. The suspending of the rear ends of the springs 10 from rail 18 eliminates any requirements for pretensioning and the ability of the spring rear end portion to move rearwardly and unwind eliminates oil canning and reduces hammocking tendencies.

In FIG. 4, a modified means of attaching the seat spring rear end portion 32 and the lower end of the back spring 24 to the frame rail 18 is illustrated. In this form of the invention, a retainer 90 is substituted for the retainer 58. The retainer 90 is similar to the retainer 58 in that it has a body portion 60 and a rear hook portion 66, but the front hook portion 64 on the retainer 58 is eliminated. The seat spring rear end portion 32 is identical to that illustrated in FIG. '2 except that it is provided with an extension consisting of spacer bars 92 and 94 and torsion bars 96 and 98. The torsion bars 34 and 96 are twisted so that the torsion bars 96 and 98 will be positioned adjacent and parallel to corresponding torsion bars 100 and 102 at the lower end of the back spring 24, which is shortened to eliminate the portion 80. Conventional spring clips .104 are then utilized to connect the torsion bar 98 to the torsion bar 102 and to connect the torsion bar 96 to the torsion bar 100. The springs 10 and 24 then operate in the same manner as described in connection with the mounting shown in FIG. 2.

FIGS. 5 and 6 illustrate other ways of mounting seat springs 10 and back springs 24 on the rail 18. In FIG. 5, the lower end of the back spring 24 is provided with a prong 106 which is pronged into a hole 108 formed in the front side 110 of the rail 18. The terminal torsion bar 34 on the seat spring rear end portion 32 is provided with a similar prong 112 which is pronged into an opening 114 formed in the top side 62 of the rail 18. In FIG. 6, the arrangement is similar to that shown in FIG. 5 except that the seat spring rear end portion 32 is shortened and a prong 116 is formed directly on the torsion bar 36 and pronged into an opening 118 in the rear side of the frame rail 18. When the springs 10 and 24 are mounted as shown in FIGS. 5 and 6, they are independent of each other so there is no requirement that they be arranged in pairs.

From the above description it is seen that this invention provides an improved seating structure in which both the seat and back springs are mounted on the lower frame rail 18 thereby obviating the necessity for extending the seat springs all the way back to the bottom frame rail 20. In can be appreciated that in some sea-ting structures the distance between the front and rear bottom rails 22 and 20, respectively, is so great that the space cannot be bridged with zigzag Wire springs.- According to the concepts of this invention, this situation is avoided because the seat springs are attached to the lower frame rail 18 which is in a more closely spaced relation with the front rail 22. In all of the forms of the invention, the rear end portion of the seat spring is suspended from the rail 18 so that it can unwind and move rearwardly as the load supporting portion 30 moves downwardly under load. This provides increased occupant comfort and eliminates any possibility of interference of the rail 18 with spring movement. It is to be understood that the shape and location of the load supporting portion 30 can be varied from what is illustrated to adapt the spring to various seating design requirements. For example, the position of the portion 30 can be varied to locate the torsion bars 40 above or below the exact positions illustrated.

It will be understood that the seat spring which is herein disclosed and described is presented for purposes of explanation and illustration and is not intended to indicate limits of the invention, the scope of which is defined by the following claims.

What is claimed is:

1. In a seating structure having upper and lower back rails, a front rail and back springs mounted on and extending between said upper and lower back rails, a seat spring mounted on and extending between said front and lower back rails, said seat spring including a main load supporting portion and a rear portion which extends rearwardly below said lower back rail thence upwardly adjacent the rear side thereof and is suspended therefrom.

Z. A seating structure comprising a supporting frame having upper and lower back rails and a front rail, a back spring mounted on and extending downwardly from said upper back rail, a seat spring mounted on and extending rearwardly from said front rail, said seat spring including a main load supporting portion and a rear portion which extends rearwardly below said lower back rail and thence upwardly adjacent the rear side thereof, and means securing the lower end of said back spring to said lower back rail and suspending said seat spring rear portion from said lower back rail.

3. A seating structure according to claim 2 wherein said securing means is comprised of a retainer mounted on said lower back rail and attached to the lower end of said back spring and the rear portion of said seat spring.

4. A seating structure according to claim 2 wherein said securing means is comprised of a retainer mounted on the top side of said lower back rail and attached to the rear portion of said seat spring inwardly from the rear end thereof, and clip means securing the rear end of said seat spring to the lower end of said back spring.

5. A seating structure according to claim 2 wherein said securing means is comprised of first prong means on the lower end of said back spring and second prong means on the rear end of said seat spring, said prong means being pronged into said lower back rail.

6. In a seating structure having upper and lower back rails, a front rail and a back spring mounted on and extending downwardly from said upper back rail, a seat spring mounted on and extending rearwardly from said front rail, said seat spring including a main load supporting portion and a rear portion which extends downwardly and rearwardly from said main portion in the undeflected position thereof, said rear portion extending rearwardly below said lower back rail and upwardly at a position rearwardly of said lower back rail, and retainer means securing the lower end of said back spring and said rear 70 portion of said seat spring to the top side of said lower back rail.

7. In a seating structure having upper and lower back rails, a front rail and back springs mounted on and extending between said upper and lower back rails, seat 75 springs mounted on and extending between said front rail and said lower back rail, each of said seat springs including a main load supporting portion and a rear end portion which extends downwardly from said load supporting portion to a position below said lower back rail thence upwardly adjacent the rear side thereof and is suspended from said lower back rail.

8. In a seating structure having upper and lower back rails, a front rail and-back springs mounted on and extending between said upper and lower back rails, seat springs mounted on and extending between said front rail and said lower back rail, each of said seat springs being formed of zigzag wire and having longitudinally spaced torsion bars connected by spacer bars, each of said seat springs including a longitudinally extending main load supporting portion which terminates at its rear end in a torsion bar and a rear end portion which extends rearwardly from said load supporting portion, said terminal torsion bar being twisted so that said rear end portion extends therefrom to a position below said lower back rail, said rear end portion having some of the torsion bars therein twisted so that said rear end portions extends rearwardly below said lower back rail and thence upwardly at a position rearwardly of said lower back rail, and means connecting the rear endmost torsion bar in said rear end portion and the torsion bar adjacent thereto to the top side of said lower back rail.

9. A seat spring having a main load supporting portion and a rear end portion, said spring being formed of zigzag wire so that it has a plurality of longitudinally spaced torsion bars adjacent ones of which are connected by spacer bars, said main and rear end portions being connected by a torsion bar which is twisted so that said rear end portion is inclined sharply downwardly and rearwardly from the rear end of said main portion at an angle thereto, said rear end portion then extending rearwardly and thence upwardly for suspension from a support.

10. In combination with a pair of horizontally spaced front and rear supports, a seat spring formed of zigzag wire having longitudinally spaced torsion bars and spacer bars which connect adjacent torsion bars, said spring having a front end mounted on said front support, a main load supporting portion and a rear end portion, said rear end portion having the torsion bars therein twisted so that said rear end portion is positioned below said rear support and extends upwardly on the rear side of said rear support, a retainer secured to the top side of said rear support and having downwardly opening hook shape end portions one of which extends rearwardly of the rear side of said rear support, said rear end portion having the next to the endmost torsion bar therein positioned in said one hook shape end portion and having the endmost torsion bar therein engaged with the top side of said retainer intermediate the ends thereof, and a back spring formed of zigzag wire and having the next to the endmost torsion bar therein positioned in the other retainer hook portion and having the endmost torsion bar therein engaged with the top side of said retainer intermediate the ends thereof.

11. In a seating structure having a main frame which includes horizontally spaced front and rear rails, a seat spring formed of zigzag wire having longitudinally spaced torsion bars and spacer bars which connect adjacent torsion bars, said spring having a front end, a rear end portion, and a main load supporting portion which extends between said front end and said rear end portion and which is generally horizontal in the undeflected position of said seat spring, means mounting said front end on said front rail, said rear end portion having the torsion bars therein twisted so that said rear end portion extends downwardly from said main load supporting portion and rearwardly below said rear rail and thence upwardly at a position rearwardly of said rear rail and thence forwardly at a position above said rear rail, a retainer having a body portion secured to the top side of said rear rail and a hook shape end portion which projects rearwardly from said rear rail, said spring rear end portion having one torsion bar therein engaged with the top side of said retainer body portion and having the adjacent torsion bar therein positioned in said hook shape end portion, said spring rear end portion having some of the torsion bars therein twisted so that in the undefiected position of said spring said one torsion bar exerts a downwardly directed force on said retainer and said adjacent torsion bar exerts an upwardly directed force on said retainer.

12. The combination according to claim 11 further including a back spring formed of zigzag wire and extending upwardly from said rear rail, and means securing a pair of back spring torsion bars to a pair of seat spring torsion bars at a position above said rear rail.

13. In a seating structure having horizontally spaced front and rear frame rails, a seat spring mounted on and extending between said rails, said seat spring having a longitudinally extending main load supporting portion which extends rearwardly from said front rail and a rear end portion which extends downwardly and rearwardly from the rear end of said load supporting and thence rearwardly below said rear rail in the undefiected position of said seat spring, and means suspending said rear end portion from said rear rail at a position rearwardly of said rear rail.

14. In a seating structure having horizontally spaced front and rear frame rails, a seat spring mounted on and extending between said rails, said seat spring having a longitudinally extending main load supporting portion formed of zigzag wire having longitudinally spaced torsion bars connected by spacer bars, said main portion extending rearwardly from said front rail and terminating at its rear end in a torsion bar, said spring having a rear end portion which extends rearwardly from said main portion below said rear rail, said terminal torsion bar being twisted so that said rear end portion extends downwardly and rearwardly therefrom, and means suspending said spring rear end portion from said rear rail at a position rearwardly of said rear rail. I

References Cited by the Examiner UNITED STATES PATENTS 2,5 32,884 12/1950 Benson 297456 2,787,317 4/1957 Vogel 267-102 2,848,038 8/1958 Bank et al. 267-107 2,855,984 10/1958 Majorana et al 267-105 3,095,189 6/1963 Slominski 267-102 3,143,339 8/1964 Flint 267-107 3,185,467 5/1965 Caughey 267-110 FRANCIS K. ZUGEL, Acting Primary Examiner.

CASMIR A. NUNBERG, FRANK B. SHERRY, Examiners, 

1. IN A SEATING STRUCTURE HAVING UPPER AND LOWER BACK RAILS, A FRONT RAIL AND BACK SPRINGS MOUNTED ON AND EXTENDING BETWEEN SAID UPPER AND LOWER BACK RAILS, A SEAT SPRING MOUNTED ON AND EXTENDING BETWEEN SAID FRONT AND LOWER BACK RAILS, SAID SEAT SPRING INCLUDING A MAIN LOAD SUPPORTNG PORTION AND A REAR PORTION WHICH EXTENDS REARWARDLY BELOW SAID LOWER BACK RAIL THENCE UPWARDLY ADJACENT THE REAR SIDE THEREOF AND IS SUSPENDED THEREFROM. 